Prior art closures having a pour spout or the like are disclosed in U.S. patent application Ser. Nos. 08/332,140 (filed Oct. 31, 1994), 08/633,225 and U.S. Pat. Nos. 5,104,008 and 5,465,876.
Some of these prior spout closures provide tamper evidency and have tamper evident pour spouts but which are not always leak proof at spout closure interface. Generally, prior art push-pull spouts that are reusable do not provide effective sealing at the juncture between the spout opening and the plug positioned in the opening when the spout is closed. Because of the very small diameter of the opening and the concern for safety, it is not possible to add non-integrated sealing means. The present invention solves this problem by utilizing a closure plug which combines a circular closure disk with an integral annular skirt depending from the periphery of the disk thereby defining a hollow cavity for the plug interior and increasing the structural flexibility of the plug. The increased structural flexibility provided by the hollow cavity causes inward deformation of the plug skirt upon engagement with annular flanges integrated into the periphery of the spout closure central opening to create a form-fitting leak tight seal.
Additionally, the present invention provides an improved means of locking the closure to a bottle neck. Projections extending radially inward from the inner surface of the tamper evident band form an upwardly angled "hook" shape for engaging the sealing flange on the bottle neck. This "hooking" engagement prevents removal of the closure while the tamper evident band remains intact.
Finally, a plurality of circumferentially spaced dimples optionally extend from the exterior wall of the pour spout. These dimples engage vertically spaced inturned annular flanges on the interior surface of the spout closure to faciliate breaking the frangible elements connecting the tamper evident band to the spout closure.
Accordingly, it is an object of the present invention to provide an effective seal for a push-pull spout for reusable containers.
It is a further object of the invention to provide a substantially leak proof tamper-evident closure having a reusable, push-pull spout.
It is a further object of the present invention to provide a reusable, push-pull pour spout closure that utilizes a closure plug having increased structural flexibility to provide a more effective leak tight seal.
It is a further object of the present invention to provide a reusable, push-pull pour spout closure that utilizes an upwardly angled locking means to prevent removal of the closure from a bottle neck with the tamper evident band intact.
It is a further object of the present invention to provide a means for faciliating the breakage of frangible elements connecting the tamper evident band to the spout closure.